Lashing out at criticism he was abandoning six trapped coal miners, the mine chief promised Wednesday to keep searching through the weekend and punch yet another hole into "this evil mountain."

Bob Murray, the face of the rescue effort since the Aug. 6 cave-in, dropped from public view for a time after three men died trying to tunnel toward the miners, but he said he's always been focused on finding the six — dead or alive.

"I didn't desert anybody," Murray, the mine's co-owner, told The Associated Press. "I've been living on this mountain every day, living in a little trailer."

A fifth borehole found only a 6-inch-deep void where it was drilled into the Crandall Canyon mine, federal officials said.

No noise was heard from the hole after a microphone was lowered and workers banged on the drill steel, said Jack Kuzar, a district manager for the Mine Safety and Health Administration.

A video camera had not yet been put down the hole Wednesday night, nor had oxygen readings been measured, Kuzar said. Earlier boreholes have revealed no signs of life and little breathable air more than 1,500 feet underground, where the miners are believed to be trapped.

"We went through the total process: Silent period, put the mic down, hitting the pipe, waiting, hitting the pipe again," said Kuzar, filling in for MSHA head Richard Stickler at a news conference. Stickler was attending the funeral for mine safety inspector Gary Jensen, one of three rescuers killed while trying to find the trapped men.

Officials said a sixth exploratory hole 1,700 feet below ground would be drilled beginning Thursday, officials said, and Kuzar said it will be in the area where the miners were last believed to have been working.

"This is the last hole," Murray said. "If we don't find anybody alive, there is nowhere else that anyone in MSHA or our company would know anywhere to drill."

Drilling that last hole, he said, will "bring closure to me that I could never get them out alive," although he acknowledged it may not bring closure to the miners' families.

"It's going to have to be in the hands of people a lot better than I am, and it's going to have to be in the hands of the Lord," he said.

Sonny J. Olsen, a lawyer and spokesman for relatives of the miners, said the families don't want the search to end until the men are found.

"Regardless if it takes three months to wait for the seismic activity to stop, they want some method to go down and get their families," Olsen said.

Murray also said he would not resume mining in any part of the mine. MSHA must decide when the mine can be sealed after it completes its investigation, he said.

"I can tell you right now, we are not going back into that mountain," he said at a news conference Wednesday night.

If investigators can't get to the point of the collapse's origin, Kuzar said, "we will never really know what happened."

The collapse that trapped the miners is believed to have been caused by settling layers of earth bearing down on the walls of a coal mine. The force can cause pillars to fail, turning chunks of coal into missiles. The unpredictable and dangerous phenomenon is known by miners as a "bump."

"Had I known that this evil mountain, this alive mountain, would do what it did, I would never have sent the miners in here," Murray said earlier. "I'll never go near that mountain again."

Murray has insisted the collapse was caused by a natural earthquake, but government seismologists say the collapse itself is what caused the ground to shake, registering a magnitude of 3.9.

Since then there have been several other bumps, including one last week that killed the three rescue workers, injured six others and led the federal Mine Safety and Health Administration to call off rescuers' efforts to dig underground.

During an AP interview in the wee hours of Wednesday, Murray described the scene of the second collapse.

He said he rushed into the mine in his street clothes and began digging out the men, buried under 5 feet of coal, with his bare hands. "I never hesitated to go in there. I was the first man in and the last man out," he said.

He said he later dropped out of a debriefing with federal officials and began wandering around the mine yard in the moonlight, reliving the collapse. He said he broke down.

"I came apart," he said. "I was under a doctor's care for a couple days."

A funeral for rescuer Gary Jensen, a mine safety inspector, was held Wednesday.

Murray, 67, has been a target of families' anger over the suspended tunneling efforts and the decision to not dig a hole big enough for a rescue capsule to be lowered into the mine. Other critics and mine experts have questioned whether mining should have been conducted at Crandall Canyon at all because of the potential for collapses.

Murray spoke bitterly of the United Mine Workers of America, which has called his company callous for planning to resume mining at other parts of 5,000-acre mine.

"They're twisting it all around to discredit me and my company," he said. He accused the union of using the disaster at the nonunion mine as a recruiting opportunity.

After the first collapse, Murray said repeatedly that the men could have survived and he would bring them home, alive or dead. But he retreated from that view after the deaths of the rescue workers.

He re-emerged Monday to announce that the trapped miners would likely remain entombed in the mine.

Murray said there was no indication before the initial collapse that the mine was anything but stable.

"I have weekly reports from the mine, and they were telling me that the mining in this mine was going better in the last couple months than it ever had," he said. "Safety first, then production. That's all we focus on, safety."

Most workers at Crandall Canyon have been given jobs at two other mines in central Utah's coal belt, although a small crew remains at Crandall Canyon, he said.